This invention relates to a waterproof connector in which a sealing member is interposed between a connector housing and an electric wire.
In a connector for interconnecting the electric wires, a crimp-style terminal is engaged therein to fix both ends of the wires to be interconnected. In order to prevent entrance of the water into the space or clearance within the connector where the crimp-style terminal is located, some connectors have a sealing member fitted into the connector housing.
FIG. 1 is a sectional view of a female connector having the sealing member therein. The electric wire 3 is inserted into a connector housing 1. The end of the electric wire 3 is connected to a crimp-style terminal 5 which is engaged with the connector housing 1. A rubber plug 7 is interposed between an insulation portion 3a of the electric wire 3 and the connector housing 1.
The rubber plug 7 comprises an electric wire insertion hole 7a passing therethrough. The diameter of the electric wire insertion hole 7a is slightly smaller than that of the insulation portion 3a. By means of forcing the electric wire 3 into the electric wire insertion hole 7a, sealing performance therebetween can be secured. Subsequently, the electric wire 3 are inserted into the connector housing 1 in this condition. Further, the rubber plug 7 is crushed in the connector housing 1, thereby the sealing performance can be exhibited to prevent entrance of the water into the inside of the connector housing where the crimp-style terminal 5 is disposed.
However, in case where a thin electric wire 3 having relatively small diameter is applied, as shown in FIG. 1, may result in a clearance t between the thin electric wire 3 and the rubber plug 7. This results in poor sealing performance.
Such rubber plug is made by using a mold 11 as illustrated in FIG. 2. The mold 11 comprises a piece 11a to form the electric wire insertion hole 7a. In order to overcome the above mentioned problem of the clearance and secure sufficient crushing of the rubber plug 7, a diameter of the piece should be further reduced. However, the piece 11a of excessively small diameter tends to be broken on making the rubber plug 7, causing inadequate productivity for the rubber plug 7. Thus, there is the limitation to an internal dimension u of the insertion hole 7a of the rubber plug 7.